<!-- 轮播图组件 -->
<script lang="ts" setup name="XtxCarousel">
import {BannerItem} from '@/types/data'
import { onBeforeUnmount, onMounted, ref } from 'vue';
// 接收父组件传来的数据
const { slides, autoPlay = true ,duration=1 } = defineProps<{
  slides:BannerItem[]
  autoPlay?:boolean
  duration?:number
}>()
const active = ref(0)
// 点击右箭头换轮播图
const zuo = () =>{
  active.value --
  if(active.value < 0){
    active.value = slides.length-1
  }
}
// 点击左箭头换轮播图
const you = () =>{
  active.value ++
  if(active.value === slides.length){
    active.value = 0
  }
}

// 组件挂载后,自动播放
onMounted(()=>{
  start()
})
// 组件卸载之前执行的函数
  //  组件结束--停止播放
onBeforeUnmount(()=>{
  stop()
})

let time = -1
  // 如果开启了自动播放,则每隔 duration 去播放下一个 hNext()

  // 鼠标离开要继续播放
const start = () =>{
  if(autoPlay){
    // 开启定时器
    time = window.setInterval(()=>{
      // 播放
      you()
    },duration)
  }
}
// 鼠标hover要暂停播放
const stop = () =>{
  clearInterval(time)
}

</script>

<template>
    <!-- @mouseleave="start"  鼠标移入  -->
    <!-- @mouseenter="stop"  鼠标移出 -->
 <div class="xtx-carousel"  @mouseleave="start" @mouseenter="stop">
    <ul class="carousel-body">
      <li 
      class="carousel-item" 
      :class="{fade: active === index }"
      v-for="(item,index) in slides " :key="item.id">
        <RouterLink to="/">
          <img
            :src="item.imgUrl"
            alt=""
          />
        </RouterLink>
      </li>
    </ul>
    <a href="javascript:;" class="carousel-btn prev" @click="zuo"><i class="iconfont icon-angle-left"></i></a>
    <a href="javascript:;" class="carousel-btn next"  @click="you"><i class="iconfont icon-angle-right"></i></a>
    <div class="carousel-indicator">
      <span
      v-for="( it,ind ) in slides " :key="it.id" 
      :class="{active:active === ind }"></span>
    </div>
  </div>
</template>

<style scoped lang="less">
.xtx-carousel {
  width: 100%;
  height: 100%;
  min-width: 300px;
  min-height: 150px;
  position: relative;
  .carousel {
    &-body {
      width: 100%;
      height: 100%;
    }
    &-item {
      width: 100%;
      height: 100%;
      position: absolute;
      left: 0;
      top: 0;
      opacity: 0;  // 不可见
      transition: opacity 0.5s linear;
      &.fade {
        opacity: 1; // 可见
        z-index: 1;
      }
      img {
        width: 100%;
        height: 100%;
      }
    }
    &-indicator {
      position: absolute;
      left: 0;
      bottom: 20px;
      z-index: 2;
      width: 100%;
      text-align: center;
      span {
        display: inline-block;
        width: 12px;
        height: 12px;
        background: rgba(0, 0, 0, 0.2);
        border-radius: 50%;
        cursor: pointer;
        ~ span {
          margin-left: 12px;
        }
        &.active {
          background: #fff;
        }
      }
    }
    &-btn {
      width: 44px;
      height: 44px;
      background: rgba(0, 0, 0, 0.2);
      color: #fff;
      border-radius: 50%;
      position: absolute;
      top: 228px;
      z-index: 2;
      text-align: center;
      line-height: 44px;
      opacity: 0;
      transition: all 0.5s;
      &.prev {
        left: 20px;
      }
      &.next {
        right: 20px;
      }
    }
  }
  &:hover {
    .carousel-btn {
      opacity: 1;
    }
  }
}
</style>